Hello to all. I am new to the forum, and starting this thread is not without some trepidation. As indicated in the heading the subject I'd like to discuss or re-discuss is the matter of hum in the power transformers on the Torii MKIV.

I have had my Torii in operation for a little over a year now. I love the sound, but became more and more distraught with power transformer hum/buzz. I had talked with Steve on three different occasions, in an attempt to figure out what I was dealing with, and if it was just me or if there really was an issue. I noted that I was not the only one having issues like this as the forum suggests.

Between the second and third contact with Steve, who led me to the belief that it may well be a "dirty power" issue, I searched the net for solutions and for possible reasons for transformer hum/buzz. There of coarse is a difference between buzz and hum. Hum is a 60 cycle issue, and buzz is 60 cycles plus harmonics, or just a lot of trash on top of the 60 Hz. Both can be an issue in power transformers for a variety of reasons. Mine fit the buzz category. My Torii was loud and annoying, and became louder the more it warmed up. It was frankly irritating and needed fixing. I tried tightening the bolts that hold the covers/plates together. I tried padding under the amp. I tried sound deadening material. I tried changing tubes. I even have an isolation transformer between the equipment and the power line. Nothing helped.

Some of the causes talked about on the internet are: loose windings, or loose plates in the transformer, dc in the power line, and dirty power (i.e. other frequencies on top of the 60 Hz), all of which have been addressed here and on other forums. Some manufacturers pour various tars, plastics etc. around their trannies in cans to mechanically dampen the vibration. Others dip the tranny in various varnishes and other goop to quiet them down. Some suggest taking the transformer apart and varnishing the plates etc. - a fast track to ruining a warrantee I'm sure .

One of the thoughts concerning what is happening in the transformer is that dc in the power line pulls the plates in the tranny to one side, skewing them, and thus causes the plates to vibrate. This I considered a real stretch - pardon the pun. But I was desperate to find a cure, so on a whim, I got some magnets and tried placing them in different places around the power transformers - I was going to pull those plates back . I placed them around the tubes and everywhere I could think of. I used magnets of every variety. I was holding a magnet that came out of a dc motor of some kind, over one of the OA3s and it accidentally slipped out of my hand and wedged between the OA3 and the right channel power transformer and lo and behold that transformer got quieter. So as not to scratch the paint on the amp, I wrapped the magnet in plumbers Teflon tape and began moving it around on the tranny. I found the best (quietest) spot and proceeded to do the same on the other power transformer. Same result. I was elated and flabbergasted. It changed the buzz into what I would consider a normal transformer hum, that was audible at 2-3feet or so from the amp, but not from 6- 8 feet away as it hand been.

Now here comes the coup de gras; the sound of the amp improved by a bunch. The high end was sweeter, the bass was cleaner and tighter. Was I dreaming? Was I experiencing some sort of self delusion? I then tried other configurations and placements, and found by ganging two round dc motor magnets together, and placing them such that they spanned the distance between the power transformers on the front side behind and in line with the OC2s, I got the best results. And, rotating them even a little would make a difference.

In a roundabout way, I sort of pulled a "double blind" on myself. I sat down to listen to some music one night and found the sound to be less appealing for some reason. In fact it sounded bad- strident, with poor sound stage and lackluster bass. What now? Then it dawned on me that I had removed the magnets because we had company over and I didn't want ugly magnets hanging from my beautiful amp. I put them back on and once again had good sound. I called Steve the next day and expected to get laughed off the planet. But he was very thoughtful, and simply said, "You may be on to something." He also suggested that I put this out on the forum to see what everyone else had to say. So here it is.

I thought about buying a power conditioner of some kind. But, what kind? The only ones that make any sense to me are the kind that change the line ac into dc and then back into ac. But those are expensive. I had a chat with my brother-in-law who is an audio engineer and owned the classical radio station here for many years (I trust what he has to say), and he said placing magnets around transformers would change things in the tranny - flux, plates etc. He provided me with a "Sniffer" which is a coil you would find in the rf section of radios, and a small battery powered amplifier. If you hold the Sniffer up to a light dimmer for example, you can here the hum it makes. This hum (and lots of others) gets into the power in your house and ultimately into your amp. Now a well designed amp like the Torii is in and of itself a power conditioner. And true to Steve's design, I get no unusual hum in my speakers (90 db sensitive). But I do get the awful tranny buzz. Using the sniffer, I found that my breaker box has hum coming from several breakers (not all) and their associated wires. One breaker feeds our WiFi extension device which is very noisy and happens to be on the same circuit as the hifi equipment.

I became rabid in my pursuit of solving the cause of my problem. I decided to run a dedicated line straight from our service box to the stereo equipment ( no small task in a flat roof adobe with brick floors). This reduced the buzz in the transformers somewhat, but not all of the time, and on occasion, I still had to use the magnets to quiet things down and to make the sound better. I can not explain why things sound good without the magnets one time and then sound better with the magnets at other times. It still may be dirty power coming from the power grid or being created by my equipment.

There are a couple of things to warn readers about. First, you can over do the size of the magnets. I have been told that the magnetic field introduced can cause the field around the transformer to kind of "seize up", perhaps by saturation, and thus cause the windings in the transformer to see a short and potentially burn up. I have not tested this theory . I have used only two magnets at a time and have experienced no abnormal temperature rise in the transformers. Second, it is a good idea to wrap the magnets in Teflon tape or some other protective coating so as not to scratch or mar the amp. Try to run "blind" listening tests, but I know you will notice the difference in any event. Will it help the sound on amps that have no abnormal hum? I don't know.

I know this all sounds crazy, but I hope those of you who are having this problem will experiment with this and relate your findings on this thread. I have no idea why this works, but the magnets must somehow "smooth" the field around the transformer, or somehow "throttle" them back, or in fact pull the plates back and keep them from vibrating, or perhaps just let them do what they are supposed to do. One last thing, I have noticed that I have less hum in my turntable motor since running the dedicated line. It was well worth the trouble running the new line. Is the next step a power conditioner?

Further research has led me to discover an issue known as DC offset. It happens in the main power line because of all the gadgets we have. For example, the switching transformers in our computers have half wave rectification and this pulls the line voltage up or down because of an imbalance and this is seen by your audio equipment as a DC voltage or rather a shift in voltage up or down on the main line AC waveform. In a transformer, the current follows the voltage 90 degrees behind and therefore is out of phase with it. Audio equipment is designed with this in mind, but if there is a shift of voltage on the main line, say upwards of a half volt or more, then the current is out of phase a different amount than the usual 90 degrees. This can be major source of distortion, and may well be what is causing the excessive hum and poor sound I am experiencing. It can also lead to an increase in temperature and or saturation in the transformer.

I have recently come upon a DC offset correcting device made by Emotiva called the CMX-2 that supposedly blocks the DC offset. The little gadget works. It has made the hum in the trannies less and has made the sound better. I no longer need to use the magnets to get good sound. In fact if I use the magnets, it sometimes degrades the sound now. The trannies are louder than with the magnets in place, but the sound is good. Perhaps the magnets can be a diagnostic tool and nothing more?

Re: A new twist on transformer hum in the Torii MKIVReply #1 - 04/04/16 at 19:40:02

Dan and I have had a little discussion over the last month or so by email, and of course his discovery caught my interest. Sweeter highs and tighter bass...that sounded good!

BTW, thanks Dan for this thoughtful and educational post! An interesting path you have taken.

My story: Before knowing the actual magnets Dan was using, I did some experiments with some 1/4" cube rare earth magnets my wife had for hanging her paper artwork on paint with iron particles in it. They are strong little magnets! http://www.rare-earth-magnets.com/magcraft-nsn0606 The size and power is very handy for trying multiple locations and identifying a good balance for sound by how many used.

I don’t have much transformer hum here, but some, and it may (?) convey a touch to the speakers, but this very quiet hum could easily be tubes. I think different tubes have caused the transformers to hum more also if I recall correctly.

With just a bit of magnet exploring I heard it right off without even backing away from the amp. Subtle in some ways, but by my experience, some subtle things can really effect the sound experience notably. With one cube on each of the plated sides (not the cover) of the MKIV's four main transformers and another two on the CSP3 transformer sides (not covers) I really liked what I got.

Compared to Dan's bigger DC motor magnets, clearly placement matters, and perhaps "less is more,” but just a couple of these per transformer sound like they are removing noise...a smoother and more resolving sound particularly calming upper range hardness/edge, it sounds like more complex edges... softer and more natural with more clear spaciousness. Also better definition throughout, especially notable in bass. Sounds similar to what Dan found right?

The other day, trying different places, I put a 3rd on the top/center of the outside MKIV transformers (I guess outputs by proximity) and the sound got a little rigid again but in a different, perhaps too densely clarified way. Then I put these two extras on the outside/right cover, right in the center of the outputs and I liked it…smooth and defined with musical body and space.

I had tried them doubled on each other on the CSP3 plates and liked that, but preferred the extras on the Torii output transformer.

Not the same, but the enhanced definition part reminds me of aspects of what I was hearing Steve's Silver Pills, something Steve thought might be associated with phase correction, and this may fit with Dan's description of DC offset issues being phase related. Though subtler here, perhaps better phase definition is happening, giving a better sense of timing all across the spectrum...though it seems clearing noise that occupied some of the edge territories could conceptually do this also. Associated, I have always preferred my PSAudio P5 phase adjustment off center, not for transformer hum issues, but because I like the sound more...decreasing noise and thus increasing complexity, texture, air and space.

I have not tried a lot of different magnet placement, liking what I got, but one day..... On quick re-testing, it is quite noticeable enough to like it better with than without. Though I have not done super serious listening tests, each time I removed the magnets I did not like what happened, today included. The sound gets surprisingly cruder (on subtle levels).

Originally, as I put them on with the transformers warm, I felt the charge between them and the transformers on my fingers when they were about 1/4 from the transformer, and it was strongish...strong enough to be a little unnerving. I wondered if they were pulling EMF/RFI that would be a negatively effecting the transformers otherwise… or aligning particle flow...like Dan suggests "smoothing the field"??? Or perhaps reducing EMF from radiating out to adjacent tubes etc??? I did not specifically notice a change in mechanical hum. And I really have no idea what is happening, but the signal is smoother and more defined, suggesting noise abatement and/or Phase related adjustments.

Whatever it is, I think Dan's discovery has stimulated a very nice improvement for me.

Re: A new twist on transformer hum in the Torii MKIVReply #3 - 04/05/16 at 00:03:27

So hard to say how much conditions effect this. But for my setup, the little 1/4" ones, though not as big, they are likely as strong by size. I think the little ones were really good here. I did not need many, and they are flexible for placement and the number used to subtly arrive at the best sound. And a few here and there actually look sort of cool.

The ones I linked are about $12 for twenty. I used 12 so far. On Ebay there are cheaper ones.

Re: A new twist on transformer hum in the Torii MKIVReply #4 - 04/05/16 at 03:27:52

Interestingly, since the transformer produces a magnetic field just by it's very nature, I hadn't about 'balancing' it, or in some way focusing it. I Might try it, but for the time, my amp is waaay ahead of me sound wise, and I had better just sit back and enjoy it.

Re: A new twist on transformer hum in the Torii MKIVReply #5 - 04/05/16 at 03:47:13

Interesting stuff. I would certainly be interested in Steve's thoughts. For the sake of clarity, I'll go back and read all of this again. Good news here is there is o hum (As of yet.) on my Tori Mk IV. However, I might be willing to place a few magnets in the pursuit of higher fidelity. That is... if there is no possibility of harming the amp. Some pics of the magnet placements might be interesting too.

Re: A new twist on transformer hum in the Torii MKIVReply #6 - 04/05/16 at 12:42:25

Very interesting but I am curious if the use of these magnets could also cause unintended problems. My knowledge of magnets is rudimentary. It seems to make sense that the magnet would be able to counteract or hold back some of the emf/rfi. In the manual it says that the transformers on the Torii IV are original to the amp and are not used on any other Decware amp.

Re: A new twist on transformer hum in the Torii MKIVReply #7 - 04/06/16 at 00:37:57

Interesting that I came across this hum issue here. I've got a 1 week old Tori Jr and the power tranny has a hum that can be heard from about 12 feet away. I just talked with Steve about this today and he was not really certain whether this could be a problem but said a certain amount of hum was normal (although he obviously wasn't in my room to hear it). So, I've also read about the DC on the power line and now that I've read what Dan gained by the DC blocking power strip, I may have to get one and try it. (I previously bought a Tripp Lite isolation transformer that everything is plugged into but still hum). I've encountered some blurry and harsh music and attributed it to the breakin which it certainly may be but if I can get rid of the hum, it may also improve the sonic quality as well. Rick

Re: A new twist on transformer hum in the Torii MKIVReply #8 - 04/06/16 at 16:32:35

Hello Rick and all,There are a couple of DC blockers that I know of out there. There may be more. One is the Emotiva CMX-2 and the other is the RPD-15 by Blue Circle. I purchased the CMX-2 as it was $100 less ($89.95 on Amazon including shipping), and it was after all an experiment. Which is better I can not say, but I am pretty happy with the CMX-2, and it physically looks better than the RPD-15. I have taken the isolation transformer out of the loop for now as well. I do plan to get some neodymium mags, like Will did, and experiment with them as well. As for now, I am only using the DC blocker and am pleased with the sound.Cheers,Dan

Re: A new twist on transformer hum in the Torii MKIVReply #9 - 04/07/16 at 21:37:43

Okay, I bit. I ordered the same magnets that Will is using. I received them today, I put them exactly where he did. Just listening to redbook and DVR so far, directly into the Torii Mk III from the PS Audio DirectStream. I do hear a bit of refined smoothening in a good way, a bit more treble ease and no sign of an edge. These are cute little magnets and so far I'd say for a total of 16 dollars a nice little improvement that I didn't know I really needed.

By the way I haven't had any transformer hum since I gave up on the Tripp-Lite isolation transformers, those really did a number on my sound in several ways. And not a good number.

And I had played around with magnets before. . . but on source players, the DEC-685 and the first Decware modded TEAC player. They did something, a little bit. but they didn't really help.

Re: A new twist on transformer hum in the Torii MKIVReply #10 - 04/07/16 at 22:28:42

Good news Lon.

I have the ones on the plate sides of the transformers about 1.25 down from the top corner, centered between the covers, and across from each other. No idea but I thought this was better than offset with one side lower and one higher. The ones on the outside covers of the outputs are pretty centered.

Since we don't really know what is happening, and preconditions vary place to place, it may be worth trying more or less in a given setting, and explore placement. I like mine where they are so much better than without, I have not searched further. I did like these plate side locations to start with though for some reason. Can't remember why.

Re: A new twist on transformer hum in the Torii MKIVReply #11 - 04/07/16 at 22:39:39

Oddly, that's pretty much how I placed them, the outside ones were a little higher so I adjusted those. Fascinating stuff. I'll play about a bit more tomorrow but I bet this is the best placement, and I like the sound a lot right now (amp has been warmed up about four hours, was a week of taking my Dad to medical things, including a 13 hour day of it yesterday, sigh).

Re: A new twist on transformer hum in the Torii MKIVReply #13 - 04/08/16 at 00:35:19

I don't do photos myself. . . . In his most recent post Will pretty much sums up where he places them and I've mirrored his placement for now. And seems like good placement, sound is noticeably changed for the better, not going to bowl anyone over, but I hear it. Only got to put about five hours on the amp today, I'll hopefully get more tomorrow.

Re: A new twist on transformer hum in the Torii MKIVReply #15 - 04/08/16 at 19:11:12

This is a fascinating thing, the sound changes from these magnets. Hard to put my finger on exactly, especially before I removed them and then re-installed them.

The sound is a bit more forward but without the slight glare and edge that "forward" usually brings with it in this system. And the center fill is more heavy. . . there's actually a touch less stereo separation but at the same time a bit more deepness to the sound behind the speakers. What's interesting is that improvements have occurred that usually come with a tonal balance variation I don't prefer. . . but in this instance I do. A good thing. Going to do a bit of placement experimentation this afternoon.

Re: A new twist on transformer hum in the Torii MKIVReply #16 - 04/08/16 at 19:29:23

By the way, connect about four of those cute little magnets together and hold them over the rectifier, regulation and output tubes on the Torii. You can feel the magnetic fields interacting, vibrating your fingers. And hear noise through the system.

I have heard "veils" of noise stripped away when I got my PS Audio Premier, then more with the P5, then more with the PowerBases and now these magnets have found another silky layer to remove. . . .

Re: A new twist on transformer hum in the Torii MKIVReply #17 - 04/08/16 at 20:41:21

I went ahead and purchased the CMX2 by emotiva and just tried it to see if it would get rid of the power tranny hum and no luck! I'm wondering if I try another rectifier tube if that may help. The noise can be heard from 12 feet away and is adding to the noise floor of the music. It does not come out the speakers and it's always there even with nothing connected to the inputs. Rick

Re: A new twist on transformer hum in the Torii MKIVReply #18 - 04/08/16 at 23:03:11

Hi Rick,When I installed the CMX-2, I could hear a lowering of the tranny hum,(not as much as with the magnets) but more importantly, the sound definitely improved. Question: Are you still using the isolation transformer? I took mine out of the loop so as to not have too many variables. I also put a ferrite on the power cord that came with the CMX-2 ( ie at the CMX-2 end of the cord). I also made up a shorter power cord and found it degraded the sound as apposed to the stock cord. Do try the magnets. As stated before, the ones I started with were circular rings that are 1.8" diam.X1"thick, and have 8 magnets around the inside of the ring. Placing it across the gap between the 2 trannies on the front just behind the OA2s would quiet the trannies a bunch. Also check to see what other electronics are on the circuit you amp is on, and eliminate them for diagnostic purposes. Try plugging only the amp into the CMX-2. And this sounds crazy, but by giving it 3-4 days of use- the transformers get quieter with time.

BTW, I found some 5/16 neodymium mags at Harbor Freight for $2.99 for a pack of 10. I fiddled with them about 4 hrs today and found a sweet spot centered on top of the plates and forward against the cover plate of each tranny. I Scotch taped them to some thin plastic fingers so I could move them around without marring the paint. Definitely a difference with and without.

And Lon, I had to move my Von Scheikerts farther appart to get the sound stage back. You are spot on with your observation that the mags move the sound stage. Why??? Cheers, Dan

Re: A new twist on transformer hum in the Torii MKIVReply #19 - 04/08/16 at 23:31:57

That's interesting your placements. . . I haven't tried those areas out yet. Pretty darned happy with the current locations Will outlined, and I don't have any transformer humming going on to try to dampen. I did alter one thing: I didn't double up on the outside transformers and just put one on each side and all in the same location, about an inch and a half from the top.

Rick, I hope you can work out your hum situation soon, and do try the magnets.

I don't know why the magnets mess with the soundstage! It's quite fascinating overall. These amps just let us hear everything!

Re: A new twist on transformer hum in the Torii MKIVReply #20 - 04/09/16 at 01:04:18

Dan,I have th CMX2 RMA # and was going to ship it back tomorrow but I'll try it again for a few days and see what it does. Yes I did bypass the isolation transformer and didn't see any change so we will see what happens. Thanks,Rick

Re: A new twist on transformer hum in the Torii MKIVReply #23 - 04/09/16 at 19:04:43

I've been following this thread with interest and I decided to try the magnets on my ZMA in the same positions as Will described for his Torii. Unfortunately, the ZMA transformers are so close together with respect to each other and to the big capacitors that there isn't room to place the magnets symmetrically.

Re: A new twist on transformer hum in the Torii MKIVReply #24 - 04/10/16 at 01:06:35

On second thought, I had some lower profile rare earth magnets (1/2 inch donuts, 1/8 inch thick) that fit between the transformers and large caps on my ZMA. I tried to follow Will's placement as I understood it. I put one on each side of each transformer, 1 1/4 inch down from the top of the transformer to the center of the magnet and centered side to side. In addition I put one on the front cover of each of the output transformers in the center of the cover. I also put them on the sides of my CSP3 and ZP3 transformers.

I can't describe in detail what I hear but I think I've picked up some clarity. It takes me too much time to put them all in place to do a meaningful A-B comparison. I'll leave them on unless someone thinks they could harm things. I have a suspicion that when I make a change like this I tend to listen more carefully and the "Improvements" that I hear may just be me really digging my equipment.

Re: A new twist on transformer hum in the Torii MKIVReply #25 - 04/14/16 at 05:01:37

Hey Archie. Sorry, my magnets were about 1 1/4” down to the top of the ¼ cube. Don't know how this might apply to yours.

Soundstage:With a few handfuls of references, I am hearing some soundstage changes, but not less width. It has been weeks since I put on the magnets though, with some tube changes, so I would have done some tuning as needed. And moving out the toe of the HR-1s a little, 1/8" or 3/16”, as well as spreading the speakers out a similar amount were likely part of this (I have reference lines on the floor). Adjusting speaker placement a little is something I often do if a tube change or something messes with the soundstage. Considering what you guys were hearing, the magnets probably led me to these changes.

I think I can say that as I move the sound darker and denser, I can sometimes lose a little too much of the upper mids to highs, and these in balance help define space and soundstage. So I often adjust fine tonal balance and subtle speaker placement with changes.

Also I have two Kemp Schumann resonators, the broadcasting wires on each side of my cabinet. I can turn their effect up a little to increase spaciousness, or down a little to restore tonal density. I balance these now and then, finding the place that is spacious, but too defuse, and then dialing it back to proper density. Then the soundstage is good as are tonal qualities. With one on each side, I can do subtle side to side tuning for soundstage balancing.

Also, at times I will run some tubes that are a little uneven, then I might adjust the CSP3 output just a touch to balance. I have it just a little stronger on the right at the moment, and if I turn it back to even, the right soundstage comes in toward center.

Anyway, without identifying it particularly with the magnets, I probably fixed whatever the magnets did.

What I am hearing so far is probably as good a soundstage as I have gotten here. I think the reduced noise from the magnets refines layer definition by increasing tonal density and spacial information...the magnets seem to get rid of riffraff noise that confuses everything, including the player placement and saturation. Here, this makes the sense of space between players a little clearer.

I think it does sound a little deeper here also, though part of this feeling may be enhanced layer definition. At the moment I think the whole soundstage has moved back a little, and with greater depth articulation, it may make the side to side placement feel less wide on some recordings. But from limited testing, these recordings feel about as wide as before, though the angle from ear to player is tighter with players back a little.

On other recordings the soundstage seems wider than usual and similar in depth, but with more spacial definition side-to-side and front-to-back.

I would say at this point, the soundstage is overall both a little wider and a little deeper, with better saturation and spacial definition. And it does all this without edginess.

I look forward to seeing how far I can take this new tuning tool, but I am on the road now, so later.

Some quick magnet placement tests: I found that my 1/4” cubes centered between covers on the plate sides and directly across from one another, the tone is densest. When they are offset the sound shifts more lean/spacious. Also...offsetting them some top to bottom, or side to side, widens the soundstage, whereas directly across deepens/narrows it. Right now, just a little offset seems to balance tonal density with a wide and deep soundstage here.

On the CSP3 I did find I liked it better with the magnets about 1.25” up from the bottom rather than the same distance down from the top (as before). The sound is more spacious and articulate but still dense and warm, and the articulation of space is clearer.

Altogether, with a bit of work, here the soundstage is off the top for this room.